Art of making iron and steel.



J. R. BILLINGS.

ART OF MAKING IRON AND STEEL.

APPLICATION FILED 1111112, 1907. RENEWED JAN.21,1910.

Patented Sept. 23, 1913.

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M fix- UNITED STATES PATENT OFFICE,

JAMES R. BILLINGS, OF BIRMINGHAM, ALABAMA, ASSIGNOR TO BILLINGS PROCESSCOMPANY, OF BIRMINGHAM, ALABAMA, A CORPORATION OF WEST VIRGINIA.

ART OF MAKING IRON AND STEEL.

Application filed May 2, 1907, Serial No. 371,386.

T 0 all whom, it may concern:

Be it known that I, JAMES R. BILLINos, a citizen of the United States,residing at Birmingham, in the county of Jefferson and State of Alabama,have invented certain new and useful Improvements in the Art of MakingIron and Steel, of which the following is a specification.

This invention relates to an improvement in the art or process of makingiron and steel, and relates more specifically to a process of treatingthe metal while in molten condition and then casting it, whereby it isgiven peculiar characteristics and at the same time rendered uniform orpracticallv uniform so far as each particular batch treated isconcerned.

Among the principal objects of the invention are to produce fromordinary and the lower grades of iron a metal possessing many, if notmost, of the valuable characteristics of steel, and which metal I term ahigh carbon steel, to provide a process which may be conveniently,rapidly and economically carried out without the necessity of elaborateor expensive apparatus; to provide a pr cess which enables the abovereferred to metal to be produced without putting it through apreliminary refining treatment, such as has heretofore been deemedessential to the production of steel; to provide a process whereby ametal may be produced having many of the characteristics of steel whileat the same time it contains what would under ordinary practice bedeemed relatively large quantities of the so-called dcbasing elements,thereby dispensin with the necessity of eliminating such de basingelements, and to a corresponding extent securing a larger yield from agiven quantity of iron; to provide a process which is capable of beingvery exactly controlled and regulated during the critical step oftreating the material; to provide a process which insures the productionof a metal admirably suited to direct casting, so that strong andperfect castings may be made from the metal direct from a blast furnaceimmediately following its treatment in accordance with my improvedprocess; to provide a process which insures the production of an iron orsemi-steel which has the characteristic of being peculiarly soft andtough, and which is therefore especially suitable for makingSpecification of Letters Patent.

Patented Sept. 23, 1913. Renewed January 21, 1910. Serial No. 539,308.

castings which require machining or tooling to finish parts thereof; toprovide a process which is capable of being varied and controlled toproduce definite desired results from varying kinds and qualities ofmetal; to provide a process which admits of sampling and determining thecharacter of the batch to be treated before subjecting it to the specialtreatment and therefore enables the latter to be varied to best suit thepar ticular batch from which the sample was taken; and in general toprovide an improved process of the character referred to.

To the above ends the invention consists in the matters hereinafterdescribed, and more particularly pointed out in the appended claims.

As is well understood in this art, iron produced by the smelting of ironores is almost invariably first made into igs or ingots and subsequentlyre-melted w on required for the various uses in the art; one important,and perhaps the chief, reason for this practice being the uncertainty ofsecuring direct from the blast furnace a metal which will produce strongand perfect castings. In the making of pig iron from the blast furnace,it is also well understood that several grades of iron will usually bepro duced from each tap-out the different grades and differentcharacteristics of each grade being due to conditions largely beyond thecontrol of the operator under the practice heretofore obtaining. Forexample, under ordinary methods now employed, it is practicallyimpossible to make all of the iron from a given tap-out of a blastfurnace so nearly of one grade as to enable it to be made into castingsdirect without incurring a high percentage of loss in poor castings.Obviously the ability to produce a practically uniform quality or gradeof iron at will is a most important desideratum, and this becomes ofincreased importance if that grade or quality be a very desirable one.

In the making of steel by the so-called direct processes, it hasheretofore, so far as I am aware, always been deemed necessary to firstsubject the molten iron to a refining process, to remove the greaterproportions of the so-called debasing impurities and to decarburize themetal; the decarburizing being usually continued until the remainingcontent of carbon is very low and the necessary amount afterwards addedby introducing a metal having a known content of carbon. Sometimes,however, the decarburizing treatment is arrested at that stage which, asnear as can be determined, will leave about the proper content in themetal. So far as I am aware, however, it has never been known, or deemedto be practical, to make from ordinary iron a metal which is in factahigh carbon steel without first speciallytreating the metal toeliminate or reduce the debasing impurities. My invention or discoverymakes this possible.

Describing this process in general terms, I first provide a batch ofmolten iron, which may be provided either by smelting ore in a blastfurnace or in any other suitable man ner, or by re-melting iron in asuitable cupola or furnace, and having thus provided the molten metal,ifit is not already in a suitable vessel I transfer it to a suitablevessel, as for example a ladle, and then subject it to that particularstep of my improved treatment which largely determines its charac'ter.This step consists in subjecting the molten metal to the actionresulting from the introduction thereto of a charge of carbon orcarbonaceous fuel, introduced in such manner and under such conditionsas to insure a rapid combustion or oxidizing action distributed withapproximate uniformity throughout the entire mass, whereby there isimmediately brought about a thorough commingling of the molten metalwith the carbon or carbonaceous material, a resulting generation ofintense heat and consequent raising of temperature of the molten iron toa relatively high degree, and the production within the mass of ron oflarge quantities of carbon dioxid.

In practice I find that the necessary rapid charging of the molten masswith carbon or carbonaceous fuel, and the obtaining of the desiredthorough combustion or oxidation to insure the production within themass of relatively large quantities of carbon dioxid, may be bestsecured by introducing the carbon in the form of pulverized charcoal,coke,

coal or graphite, downwardly against the ferrostatic pressure of themolten iron, and in such manner that it will be discharged or set freeand distributed throughout the lower portions of the mass, while at thesame time I introduce controlled and limited quantities of air toaugment the supply of oxygen. The air should also be so introduced as tobe disseminated throughout the mass of metal, and to this end I find itmost convenient to introduce the air under pressure through a downwardlyextending pipe arranged to discharge near the bottom of the vessel. Thetreatment should be of comparatively short duration, and the objectaimed at is not to carburize the iron or add to its total content ofcarbon, but rather to produce within the mass of metal the intense heatincident to the oxidation of the fuel into carbon dioxid, and to producewithin the metal the dioxid, which is a most important factor insecuring the desired result. Promptly after the charge of carbonaceousmaterial has been introduced in the manner described, and as soon as thetemperature of the metal has been raised to a high degree thereby, theintroduction of the carbonaceous fuel is arrested, as well also as theintroduction of oxygen, and immediately, and while the metal is heavilycharged or impregnated with the resultant carbon dioxid, I pour it intothe molds, which may be either molds for forming pigs or ingots, ormolds for forming castings of mechanical parts. I have obtained the bestresults by using metal molds, which, before receiving the molten metal,have been warmed to a moderate temperature, say from 150 to 200 degreesFahrenheit, so thatwhile the castings werenot chilled and therebyhardened they were nevertheless cooled with considerable rapidity. Themetal molds should also be protected with a wash or coating, such asraphite or the like, to prevent the molten metal from sticking to themolds.

lVhile from the nature of the subject it is difiicult or impossible tosay exactly what reactions and changes take place during the treatmenthereinbefore described, and which producethe characteristic resultsachieved by my process, yet I believe the following is in general asubstantially correct explanation: Molten iron, when tapped from theblast furnace, or when melted in a cupola or other ordinary meltingdevice, holds a large proportion of-its carbon in the carbonic oxidstate and is ordinarily of a temperature of from 2000 degrees Fahrenheitto possibly 2500 degrees Fahrenheit. Upon the rapid introduction of thecharge of free carbon, accompanied by a suflicient supply of oxygen, asdescribed, the resulting oxidation greatly increases the heat andconverts the carbonic oxid present into carbon dioxid or carbonic acidgas; and this latter, by the subsequent prompt pouring and rapid coolingof the metal, is largely retained in the metal and imparts thereto thepeculiar characteristics. to the metal.

I have demonstrated that an iron containing a total carbon content of3.50, silicon 2.,

sulfur .15, phosphorus 1.25, and manganese would be considered acomparatively low grade of steel yet nevertheless a steel. With basiciron having an analysis of 3.25 total carbon, 1.00 silicon, .05 sulfur,.5 phosphorus and 1.00 manganese, I produce a fairly good casting steelhaving a tensile strength above 30,000 pounds per square inch. I havefurther demonstrated that taking the metal as it is tapped out from agiven blast furnace, and treating the several tap-outs in accordancewith my process, I can so uniform the product that for ordinary foundrypractice it will all pass as of one grade. By this I .do not mean to beunderstood as saying that the iron thus treated will all be of the samechemical analysis, but what I do mean is that the iron so produced willall be practically uniform in its working qualities, and this metalwhile not exactly like any of the grades of metal which are commonlyknown nevertheless has such characteristics that it has been pronouncedas of very high grade.

Inasmuch as it is generally conceded by the best authorities that lackof uniformity in the product from a given blast furnace, or giventap-out, is due to changes in temperature and conditions largely beyondthe control of the operator and not so much to the chemical compositionof the metal, it will be seenthat the results secured by my processare-of great importance, because I am able to take the molten metal asit comes from the blast furnace and so subject it to controlledconditions as to secure practical uniformity.

Another and important characteristic of the metal produced in accordancewith my process is this: When the metal is re-melted in the foundry oreupola it comes down or melts in a condition much hotter and more fluidthan the usual irons with the result that perfect castings can be madewith less care, and under more adverse conditions, than when using theusual crude pig irons or mixtures.

The process may perhaps be more exactly described and better understoodby a description thereof as carried out in conjunction with one form ofsuitable apparatus used for subjecting it to what I term the convertingstep.

In the accompanying drawingsFigure 1 is an axial sectional View of aladle and suitable apparatus for introducing air and a metalloid; anordinary blower forming a part of this apparatus being shown in sideelevation; Fig. 2 is a plan view of the introdueing mechanism pertainingto the ladle and shown in Fig. 1; Fig. 3 is a perspective of a sheetmetal cap used for closing the lower end of the introducing tubetemporarily.

In this apparatus, 1 designates the ladle, which may be of any usual andsuitable type, 2 a platform constructed to extend above the ladle andprovided with an aper ture 3 through which the introducing tube may beinserted, 4 the introducing tube as a whole, and 5 a supporting frame,conveniently taking the form of a box, through the lower end of whichthe introducing tube extends and to which it is rigidly united, by screwthreads as shown.

The frame 5 1s detachably held in place on the platform by means of aset of hooklinks 6; the arrangement being such that when a charge ofmetal is to be treated, after it has been placed in the ladle, theintroduc ing tube is lowered through the platform and into the moltenmass, and the frame 5 then locked to the platform by the hooklinks.

The introducing tube comprises an inner metal tube 7, an outerconcentric metal tube 8 spaced away from the inner tube so as to form anannular air passage 9 therebetween, and an outer refractory covering 10which covers so much of the tube as is liable to be inserted in themolten metal. The upper and lower ends of the annular space 9 are closedby space rings 11, 11, through which may be extended the rivets 12 whichsecure the inner and outer tubes together. A circumferential series ofoutlet openings 13 afford communication between the lower end of theannular space 9 and the interior of the inner tube. lVith the upper endof the same space communicates an inlet pipe l-l which is connected bymeans of a flexible pipe or hose 15 with any suitable source of air oroxidizing blast under pressure. An ordinary positive blower 16 is shown.The blast is controlled by means of an ordinary turncock or valve 17which is so constructed that the blast may be both turned on and oil andgraduated.

Within the inner tube is arranged to reciprocate an ejector plunger 18,the stem 15) of which is in the form of a rack which extends upwardlythrough the frame 5 and meshes with a spur-gear 20. (iear 20 is mountedon a crank-shaft 21 journaled to extend transversely through the frameand conveniently operated manually by means of a crank-handle 22. Aroller 23 jourualed in a cross frame strip 5' ust back of the rack 19holds the latter in mesh with the gear. A tin or sheet iron cap 2 isprovided, which is constructed to fit tightly upon the lower end of theintroducing tube and serves to hold the charge of carbon within the tubeafter it has been placed therein.

The process as carried out with the foregoing apparatus is substantiallyas follows: A suitable batch of metal having been charged into theladle, and the requisite amount of pulverulent charcoal, graphite, orother comminuted carbonaceous metalloid placed in the delivery end ofthe introducing tube, and confined therein by placing the cap 24 uponthe end of the tube, the latter is lowered through the platform into themetal and the frame made fast, As soon as the lower end of the tube isfairly within the molten metal the cap 24 will be melted oil, thusexposing the metalloid to the action of the molten metal.

The operators will now commence to force the ejector plunger downgradually and at the same time introduce a regulated quantity of air byopening the turncock 17 to the desired extent. It will be obvious thatthe carbon and the supply of oxygen will be thus introducedsimultaneously, under perfect control and in regulated proportions as toeach. hen properly manipulated, the resultant reaction will effect analmost perfect combustion of the carbon so introduced, and conversion ofthe latter int-o carbon dioxid. The incident generation of gases,ebullition and ferrostatic pressure of the molten mass effects a verythorough dispersion and dissemination of the carbon and gases evolvedtherefrom throughout the entire contents of the ladle, Moreover, thecirculation of the molten mass inducedby the very considerable increasein temperature and ebullition will also aid in bringing about a mostthorough and uniform treatment of all parts of the mass.

It is to be understood that the treatment should be carried out underthe eye and control of the operator, who will be able to determine themoment the charge of metalloid has been exhausted by the action andappearance of the metal. If necessary or desirable a second charge ofcarbon may be introduced by simply withdrawing the plunger, placing thecarbon in a tube and again forcing down the plunger to expel the same.lowever, in practice a measured charge is used which is made to conformto the quantity of metal to be treated and the necessity of repeatedcharges thus avoided. As soon as the treatment has been completed the introducing tube with its connected frame and parts is lifted out of theladle and the metal immediately poured either to form pigs or ingots, ormechanical castings, as the case may be.

I claim as m invention 1. The improvement in the artof making iron whichconsists in first obtaining the metal in a molten mass, confining themass in a suitable receptacle, then while so confined, rapidly but underregulable control, introducing and thoroughly dispersing through allparts of the mass carbon or carbonaceous fuel and simultaneouslyeffecting the generation of carbon dioxid and heat by concurrentlyintroducing and dispersing through the mass under regulable controloxygen under a pressure not greatly in excess of the ferrostaticpressure and in quantities limited to conform approximately to theamountnecessary to effect substantially complete combustion of thecarbon or fuel so introduced.

2. The improvement in the art of making iron which consists in firstobtaining the metal in a molten mass, confining the mass in a suitablereceptacle, then while so confined, rapidly but under regulable control,positively forcing downwardly into the molten iron against the upwardlydirected ferrostat-ic pressure thereof a quantity of comminuted carbonand allowing regulated portions of the carbon to escape and rise freelythrough the molten iron, and simultaneously forcing into said batch ofmolten metal against the ferrostat-ic pressure and not greatly in excessthereof and under regulable control air in quantities conformingapproximately to the amount necessary to effect substantially completecombustion of the carbon and the production of maximum quantities ofcarbon dioxid, and then promptly and while the mass is heavily chargedwith said carbon dioxid converting the iron into castings.

3. The improvement in the art of treating iron, which consists in firstobtaining the iron in a molten mass and confined in mass condition in asuitable receptacle, then treating the mass to simultaneously raise thetem perature thereof and impregnate the same with carbon dioxid, bydisseminatmg throughout the charge finely divided carbonaceous materialand oxygen, in proportions to produce and maintain during the reactiontreatment quantities of carbon dioxid in the mass in excess of thatwhich the direct chemical reaction demands, the quantities of oxygenintroduced being restricted so as to avoid pronouncedly oxidizing theiron during such treatment.

at. The improvement in the art of making iron and steel, which consistsin diffusing throughout the iron, under controlled conditions, withaccompanying limited quanti-- ties of oxygen, and while the iron isfully molten, material which produces in the presenceof the iron andoxygen an exothermic reaction and provides quantities of carbon dioxidin the mass in excess of that which the direct chemical reactiondemands, and maintaining said treatment and the molten metal and carbondioxid in intimate combining relations until the iron has been pro-ALBERT H. GRAVES, EMILIE ROSE.

